From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50709) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzkUp-0007MM-6G for qemu-devel@nongnu.org; Wed, 25 Jun 2014 06:32:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WzkUh-0002Ae-OT for qemu-devel@nongnu.org; Wed, 25 Jun 2014 06:32:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:2908) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzkUh-0002AW-FN for qemu-devel@nongnu.org; Wed, 25 Jun 2014 06:31:59 -0400 Date: Wed, 25 Jun 2014 13:32:11 +0300 From: "Michael S. Tsirkin" Message-ID: <20140625103211.GA6884@redhat.com> References: <53AA8E7D.809@intel.com> <20140625090925.GH32652@redhat.com> <53AA9480.1010005@intel.com> <53AA96DF.6070501@redhat.com> <53AA9B58.6050803@intel.com> <20140625095533.GE6357@redhat.com> <53AA9D79.3080003@redhat.com> <53AA9F3A.5030004@intel.com> <20140625102119.GJ6357@redhat.com> <53AAA452.2090301@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53AAA452.2090301@intel.com> Subject: Re: [Qemu-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Chen, Tiejun" Cc: peter.maydell@linaro.org, xen-devel@lists.xensource.com, stefano.stabellini@eu.citrix.com, allen.m.kay@intel.com, Kelly.Zytaruk@amd.com, qemu-devel@nongnu.org, anthony.perard@citrix.com, anthony@codemonkey.ws, yang.z.zhang@intel.com, Paolo Bonzini On Wed, Jun 25, 2014 at 06:28:34PM +0800, Chen, Tiejun wrote: > On 2014/6/25 18:21, Michael S. Tsirkin wrote: > >On Wed, Jun 25, 2014 at 06:06:50PM +0800, Chen, Tiejun wrote: > >>On 2014/6/25 17:59, Paolo Bonzini wrote: > >>>Il 25/06/2014 11:55, Michael S. Tsirkin ha scritto: > >>>>>You're saying we will reserve a free BAR to address those > >>>>information to > >>>>>expose to guest, but which device does this free BAR belong to? The > >>>>video > >>>>>device? Or PCH/MCH? > >>>> > >>>>If you just want to pass a couple of IDs, then don't, it's a waste. > >>>>But I still don't know what problem you are trying to solve, > >>>>looking at guest driver did not help. > >>> > >>>It's not just a couple of IDs, it's also random fields of the MCH > >>>configuration space. Grep drivers/gpu/drm/i915 for bridge_dev. > >>> > >> > >>Paolo, > >> > >>No, we're not pointing the bridge_dev here, which is a host bridge at > >>00:00.0. > >> > >>Here it should be a ISA bridge at 00:1f.0. Please see intel_detect_pch() to > >>know why we need this. > >> > >>Thanks > >>Tiejun > >> > > > >So what if you dont? > > > > if (!pch) > > DRM_DEBUG_KMS("No PCH found.\n"); > > > >Is that all? Seems harmless enough. > > > > I don't read the whole driver completely so I don't know now. I guess the > driver may go other live path even without this setting in a live, or this > is a real bug to this driver on Intel platform. > > But anyway, I think we should guarantee the driver work under the same > configuration as the native in the passthrough case. > > Thanks > Tiejun Just get it working as a first step. Then address theoretical issues in follow-up patches. -- MST From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [v5][PATCH 0/5] xen: add Intel IGD passthrough support Date: Wed, 25 Jun 2014 13:32:11 +0300 Message-ID: <20140625103211.GA6884@redhat.com> References: <53AA8E7D.809@intel.com> <20140625090925.GH32652@redhat.com> <53AA9480.1010005@intel.com> <53AA96DF.6070501@redhat.com> <53AA9B58.6050803@intel.com> <20140625095533.GE6357@redhat.com> <53AA9D79.3080003@redhat.com> <53AA9F3A.5030004@intel.com> <20140625102119.GJ6357@redhat.com> <53AAA452.2090301@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <53AAA452.2090301@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org To: "Chen, Tiejun" Cc: peter.maydell@linaro.org, xen-devel@lists.xensource.com, stefano.stabellini@eu.citrix.com, allen.m.kay@intel.com, Kelly.Zytaruk@amd.com, qemu-devel@nongnu.org, anthony.perard@citrix.com, anthony@codemonkey.ws, yang.z.zhang@intel.com, Paolo Bonzini List-Id: xen-devel@lists.xenproject.org On Wed, Jun 25, 2014 at 06:28:34PM +0800, Chen, Tiejun wrote: > On 2014/6/25 18:21, Michael S. Tsirkin wrote: > >On Wed, Jun 25, 2014 at 06:06:50PM +0800, Chen, Tiejun wrote: > >>On 2014/6/25 17:59, Paolo Bonzini wrote: > >>>Il 25/06/2014 11:55, Michael S. Tsirkin ha scritto: > >>>>>You're saying we will reserve a free BAR to address those > >>>>information to > >>>>>expose to guest, but which device does this free BAR belong to? The > >>>>video > >>>>>device? Or PCH/MCH? > >>>> > >>>>If you just want to pass a couple of IDs, then don't, it's a waste. > >>>>But I still don't know what problem you are trying to solve, > >>>>looking at guest driver did not help. > >>> > >>>It's not just a couple of IDs, it's also random fields of the MCH > >>>configuration space. Grep drivers/gpu/drm/i915 for bridge_dev. > >>> > >> > >>Paolo, > >> > >>No, we're not pointing the bridge_dev here, which is a host bridge at > >>00:00.0. > >> > >>Here it should be a ISA bridge at 00:1f.0. Please see intel_detect_pch() to > >>know why we need this. > >> > >>Thanks > >>Tiejun > >> > > > >So what if you dont? > > > > if (!pch) > > DRM_DEBUG_KMS("No PCH found.\n"); > > > >Is that all? Seems harmless enough. > > > > I don't read the whole driver completely so I don't know now. I guess the > driver may go other live path even without this setting in a live, or this > is a real bug to this driver on Intel platform. > > But anyway, I think we should guarantee the driver work under the same > configuration as the native in the passthrough case. > > Thanks > Tiejun Just get it working as a first step. Then address theoretical issues in follow-up patches. -- MST